Jaffna Tamil is often mistaken for Malayalam in Tamil Nadu:
Why is that? Pittu, idiyappam, coconut flavouring, etc is especially common in Tamil regions of Sri Lanka as well as Kerala afterall – there’s got to more to this.
There’s some talk of overlap between the communities historically, ie. “a royal lineage of Malyyers” from Jaffna: Malayalees?; Ezhavas, Thiyas & Eelam & Tivus? Need to dive into this more, comment with credible sources!
This could go way deep:
The Chera kingdom’s symbol was a bow & arrow. Archer = Ilava <- Vilava <- Bhil (different communities from deep historical times, listed from south to north India).
Comparative linguistics analysis is critical
Normally, vocabulary transmission is easier with contact. Whereas grammar & phonemes aren’t.
Jaffna Tamil & Malayalam are not mutually intelligible. The similarity is more in the SOUND, ie. intonation, phonemes. This, along with some shared archaic words reflect a deep history. Does this mean Jaffna Tamil is an older form of Tamil, one that Tamil Nadu’s tongues developed away from over time?